Apparatus for fabricating ladders for venetian blinds



C. J. DELEGARD APPARATUS FOR FABRICATING LADDERS April 8, 1952 FOR VENETIAN BLINDS 4 Sheets-Sheet 1 Filed Jan. 5, 1950 INVENTOR.

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April 8, 1952 c. J. DELEGARD APPARATUS FOR FABRICATING LADDERS FOR VENETIAN BLINDS 4 Sheets-Sheet 2 Filed Jan. 5, 1950 INVENTOR. (222i J2 .LZ

April 8, 1952 I c. J. DELEGARD APPARATUS FOR FABRICATING LADDERS FOR VENETIAN BLINDS 4 Sheets-Sheet 3 Filed Jan. 5, 1950 QWN INVENTOR.

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Patented Apr. 8, 1952 APPARATUS FOR FABRICATING LADDERS FOR VENETIAN BLINDS Carl J. Delegard, Chicago, Ill.

Application January 5, 1950, Serial No. 136,955

5 Claims. (01. 154--1.6)

My invention relates to Venetian blinds and includes among its objects and advantages an improved construction of the ladder tapes forming part of an assembled Venetian blind, and a process and apparatus for the production of the improved ladder tapes.

In the accompanying drawings,

Figure 1 is a partly diagrammatic plan view of an apparatus according to the invention;

Figure 2 is a side elevation of the same apparatus;

Figure 3 is a somewhat enlarged section on line 3-3 of Figure 2;

Figure 4 is a more greatly enlarged fragmentary cross section on line 4-4 of Figure 2;

Figure 5 is a fragmentary schematic diagram indicating the movement of the strips from which the ladder tape is formed;

Figure 6 is a side elevation of a section of ladder tape produced according to the invention;

Figure 7 is a perspective view of a short section of ladder tape; and

Figure 8 is a simplified schematic diagram of the spacing blocks and their movement.

For convenience in understanding the invention clearly, reference is had first to the diagrams of Figures 5 and 8. A series of steel blocks l rests on a support [2. Each of the blocks has the shape of a rectangular parallelpiped except that its advancing, or right hand, face, as seen in Figure 8, is offset slightly over the upper two-thirds of the face, as indicated at [5, to define a narrow slot between the ofiset portion and the rear face of the adjacent block, in which slot the ladder tapes are housed during the process of making the complete ladder tape assembly. Thus, as indicated in Figure 5, an upper ladder tape [4 is withdrawn from suitable or conventional storage and passed around a guide roller l6 and between longitudinally spaced pairs of movable idler guides l8 and 20. In the, position of Figure the tape M then passes across behind the forming block |U-2, along its near side and back across between it and the next block Il]4, and so on, in zig-zag relationship indefinitely. Similarly, a duplicate narrow strip of material 22 constituting the lower ladder tape is guided around a companion guide roll 24 and through guides 26 and 28. As illustrated in Figure 5, it is thus disposed on the near side of the next block I0-20 to be inserted in the series, and passes across behind block Ill-2 to the far side and longitudinally forward to return to the near side between blocks Ill-2 and Ill-4.

For convenience, the succeeding blocks in Figure 5, are numbered I8B, Ill-8, and so on. At or about the position of block Ill-6, side tapes are guided into juxtaposition with the ladder tapes l4 and 22. I have indicated a near side tape 30 and a far side tape 32 which join the ladder tapes and move with them step by step to the right thereafter. I

The movement necessary to build the tape ocours in step-by-step fashion by progressively inserting a new block, indicated at I020 in Figure 5, in the space between the ladder tapes, where they are held apart by the guides Iii-20 and 262'8. Then the newly inserted block is pushed to the right into the position occupied in Figure 5 by the block Iii- 2, and after that movement is completed, the upper guides 18 and 20 slide across to the near side, and the lower guides 26 and 28 slide across to the far side. This wraps the ladder tapes around the newly inserted block and separates them in reversed relationship for the insertion of still another block, and so on.

The time sequence of operations, beginning with the parts in the position indicated in Figure 8, may be as follows: (1) Spaced vertically moving plungers 34 and 36 push the block at the right end of Figure 8 down out of engagement with the formed ladder tape until it comes to rest on a conveyor chain 38, by means of which it is carried back to the left to join a reserve or storage supply of blocks indicated at 4!]. (2) The plungers 34 and 36 move up again to the position of Figure 8 so that there is clearance for the upper row of blocks to move to the right again. (3) The advancing plunger 42 engages the left end of the upper row of blocks and pushes them over a horizontal distance equal to the dimension of one block, and then returns to the position indicated in Figure 8. (4) The lifting plunger 44 picks up the next storage block l9-2B and moves it up to the upper level between the ladder tapes 22 and I4.

Ihis completes the cycle of movement of all the parts shown in Figure 8, and the next step is to start another cycle by movement of plun ers 34 and 36. But it will be noted that except during the advancing stroke of plunger 42, the blocks of the upper level are stationary. At any time during the relatively long period when these blocks are stationary, frequency welding shoes I I6 are advanced into contact with the side tapes 30 and 32 respectively- Thus the appropriate reach of ladder tape lying in contact with the side tape may be subjected to heat developed interiorly by high frequency potential of the order of magnitude of 30 megacycles, operating between the welding shoe and the block I through the dielectric constituted by the side tapes and ladder tapes themselves. It will be obvious either the side tapes or the ladder tapes, or both, must be of material that can be softened and welded by gentle heating, such, for instance, as any of the common plastic materials well known in the art.

It will be obvious that the manipulations of the tapes and blocks could be performed almost entirely by hand, with the operator setting the new blocks in place and securing the ladder tapes from storage spools which he would move by hand after pushing the blocks along the guide way. And the same operator, or another operator, could work along the side of the row of blocks to weld the ladder tapes to the side tapes with a flat iron or equivalent heating means.

Figures 1 to 4 inclusive indicate machinery for performing the process on an entirely automatic basis. The main frame of the machine is a pair of channels 50 and 52 set back to back and defining a longitudinal space closed at the bottom by a downwardly opening bridge channel 54. The

support I2 of Figure 8 may be a pair of shoulders projecting inwardly from spaced risers 5B. The main frame may conveniently be supported at a desired height by a suitable structural frame including legs 58 and cross braces 60 defining a lower platform to support a conventional motor 62 operating through a speed reducer 64 to drive the main cam shaft 66.

The lifting plunger 44 is shown in Figures 2 and 3. It extends up through an aperture 61 in the web of the channel 54 and has a bifurcated lower end 10 straddling the cam shaft 66. The -cam 68 engages the contact roller II to lift the plunger, and the speed of operation is such that it is practical to let the plunger descend by gravity. The cam 68 may be formed integral with or integrally united with the same sleeve I2 carrying the sprocket wheel I4 by means of which the shaft 66 receives power from the motor.

The plunger 42 is connected to the upper end of a vertical lever I5 extending above and below its fixed pivot I6. A tension spring 18 extending between the frame and the lower end of the lever 75 normally holds the plunger in retracted position. The pitman 80 extends horizontally in from the downwardly projecting arm of the lever I5 and has a bifurcated end 82 (see Figure 3) also straddling the shaft 66. An actuating cam 83 engages a contact roller 85 to complete the mechanical connections for reciprocating the plunger 42.

As clearly indicated in Figure 3, the ends of the shaft 66 transmit movement through bevel gears to a vertical shaft 84 for actuating the crossslide 86 carrying the roller guides I8 and 20. At the other end a duplicate shaft 88 is similarly driven, and transmits its motion to the roller guides 26 and 28 for the lower ladder tape by means of the cross slide 90. The cross slides 86 and 90 carry contact rollers 92 and 94 engaging the faces of actuating cams 96 and 98. I have illustrated simple contact cams and tension springs I00 and I02 for holding the rollers 92 and 94 in contact with their cams.

Electronically, the welding equipment may be conventional. As best indicated in Figures 1 and '4, a guide block I04 of insulating material provides mechanical guides for the in and out movement of an upper electrode I06 and a lower electrode I08. A duplicate guide block IIO guides a duplicate upper electrode H2 and a lower electrode lI4. Each electrode carries a contact head II6 of conducting material, and the electrodes are of conducting material and slidable in the fiber blocks I04 and H0. At their remote ends the electrodes carry contact rollers II8 of insulating material, and tension springs I 20 hold the electrodes in retracted position except when they are forced forward by the actuating cam I22.

A suitable mechanical transmission is provided for the cams I22. A cross shaft I24 in the vertical plane of the cams I22 receives power from the main shaft 66 by means of a sprocket I26. At its ends it is connected to vertical shafts I28 carrying the cams I22.

It will be obvious that the cams are laid out so that during one of the stationary periods for the blocks I0, the electrodes I06 and H4 will be advanced to weld the upper ladder strip on the near side and the lower ladder strip on the far side. At this time there is no ladder strip opposite the electrodes I08 and H2. During the next rest period of the blocks I0, both ladder tapes have crossed over, and the electrodes I08 and I I2 are advanced into operative position while electrodes I06 and H4 remain inactive. It is convenient to make the cams I22 or the rollers II8 orboth of insulating fiber, and to connect the high frequency power supply lines direct to the.

electrodes, which are thus insulated from the rest of the machine. The other terminal of the high frequency line can be connected to the frame of the machine because the blocks I0" are effectively grounded on the shelves I2.

The means for actuating the plungers 34 and 36 include a cross shaft I30 driven from the cross shaft I24 from the other sprocket I32 on that shaft. These plungers move up and down together in unison and may be connected by a pair of riser rods I34. The lower plunger 36 may be bifurcated and straddle the shaft I30 and carry a contact roller I36 riding on the cam I38.

For bringing the blocks I0 back under the support I2 the sprocket chain 38 is provided in duplicate as clearly indicated in Figure 3, and slides on the upper surface of the web of the channel 54. The means for actuatingit include a live sheave I40 driven from the main shaft 66 and an idler sheave I42 at the other end.

The upper ladder I4 may be supplied from a storage roll I42 and the lower ladder tape from a storage roll I44. These rolls may be separate structures, but I prefer to mount them on bracket arms I46 at the end of the main frame. Similarly, the side tape 30 may be supplied from a storage roll I48 and pass round an idler guide pulley I50 by means of which it is laid snugly alongside the blocks I0 and the ladder tapes already threaded over the blocks. A duplicate storage roll I52 and guide roller I54 provides the other side tape 32. The withdrawal of the ladder tapes and the side tapes from the supply means takes place automatically, due to the pull exerted when the blocks I0 are advanced.

After the tape is completely formed and has passed beyond the plungers 34 and 36, it is no longer held distended by the blocks and is ready to be put in storage for subsequent use. I have indicated a receiving spool I56 conventionally driven with light friction in the direction of takeup as by means of a cross shaft I50 driven from the cross shaft I30, and bevel gearing connecting the cross shaft I58 with the vertical spindle I60.

A suitable friction connection results from having the spool merely laid in place on a turntable 162 so that the frictional contact between the spool and the turntable rotates the spool. After the finished ladder tape passes the plungers 34 and.36, the side tapes are no longer held away from each other, and they will bedrawn toward each other as clearly indicated by the tapering reach, at I64 in Figure 1 as they are wound up on the delivery spool.

.The sets of reciprocating guides 18,, 25 and 26,

28, function as weaving means for lacing the ladder tapes l4 and 22 to and fro. When a source of power is available, the mechanical transmission means interconnecting all the parts, actuates them in a predetermined time sequence and thus .makes the weaving means automatic. 1 Others may readily adapt my invention for use under various conditions of service by employing one or more of the novel features involved or, equivalents thereof. For instance, the method could be practiced without anyblocks at all, by drawingall four strips of material from storage rolls kept under light tension. A simple expanding pliers with flat ends to engage the ladder strips could push them to either side into contact with either thermal or electric welding shoes. After each welding the ladder tapes could be crossed by hand, and the strips pulled along one space into position for the next weld. As at present advised with respect to the apparent scope of my invention, I desire to claim the following subject matter.

I claim:

l Equipment for fabricating ladders for Venetian blinds comprising, in combination? a series of filler and spacer blocks; each block having a filler portion shaped to define a rectangular space equal to the space between successive cross connections of the finished ladder in use; each block including an extension below said filler portion, available for manipulation of said block; guide means for supporting a series of said blocks juxtaposed in a horizontal row; said extensions being shaped to abut each other in said row; said filler portions being shaped to define narrow trans verse spaces between adjacent filler portions for receiving the crossing portions of ladder tapes; advancing means for intermittently advancing said rowlongitudinally a distance equal to one block; side tape feed means for positioning side tapes along said row of blocks adjacent the filler portions of said blocks; ladder tape feed means operating in advance of said side-tape feed means for feeding an upper ladder tape in a zone adjacent the upper edges of said side tapes and a lower ladder tape in a zone adjacent the lower edges of-said side tapes; said upper and lower zones being spaced apart; automatic weaving means operating back of the rearmost block in said row for carrying each ladder tape across from one side to the other behind said last block; automatic inserting means for movinga new block upward from below into the space between said crossed ladder tapes; said advancing means operating after said inserting means to engage the newly inserted block and force it to join the row and push the row forward; automatic withdrawal means operating in timed sequence before said advancing means, forwithdrawing the leading block of the row; and automatic afiixing means in the nature of electronic welding electrodes operating after each actuation of said advancing means and before the succeeding operation of said advancing means for afiixingsaid side tapes to the ladder tape sections in contact with said side tapes; said electronic welding means including an upper shoe and a lower shoe on each side, each shoe extending longitudinally through the length of one block; and cam means for actuating an upper welding shoe on one side and a lower welding shoe on the other side during one rest period of said row and a lower shoe on said first side and an upper shoe on said second side during a succeeding rest period; automatic means including a slip friction drive for winding upthe finished ladder coming from said row; return conveyor means for returning blocks withdrawn from the front of said row and carrying them back to be delivered to said inserting means; and means'for actuating the moving elements or said equipment in predetermined time sequence.

2. Equipment for fabricating ladders for Venetian blinds comprising, in combination: a series of filler and spacer blocks; each block having a filler portion shaped to define a space corresponding to the space between successive cross. connections of the finished ladder in use; each block including an extension below said filler portion, available for manipulation of said block; guide -means for supporting a series of said blocks juxtaposed in a horizontal row; said extensions. be-

ing .shaped to abut each other in said row;.said

filler portions being shaped to define transverse spaces between adjacent filler portions for receiving the crossing portions of ladder tapes; advancing means for intermittently -"advanci.ng said row longitudinally a distance equal to one space; side tape feed means for positioningside tapes along said row of blocks adjacent the filler portions of said blocks; ladder tape feed means operating in advance of said side tape feed means forfeeding an upper ladder tape in a-zone adjacent the upper edges of said side tapes and a lower ladder tape in a zone adjacent the lower edges of said side tapes; said upper and lower zones being spaced apart; weaving means-opcrating back of the rearmost block in said row for carrying each ladder tape across behind said last block; inserting means, for moving a new block upward from below into the space between said crossed ladder tapes; said advancing means operating after said inserting means to engage the newly inserted blockandforce it to join the row and push the row forward; automatic withdrawal means operating in timed sequence before said advancing means, for withdrawing the leading block of the row; and automatic affixing means inthe nature of electronic-welding electrodes operating after each actuatio-n of said advancing means and-before the succeeding operation of said advancing means for aff xing said side tapes to the ladder tape sections in contact with said side tapes; said electronic welding means including an upper shoe and a lower shoe on each side, each shoe extending longitudinally through the length of one block; cam means for actuating said shoes in predetermined timed sequence; conveyor means for returning blocks withdrawn from the front of said row and carrying them back to be delivered to said inserting means; and means for actuating the moving elements of said equipment in predetermined time sequence.

3. Equipment for fabricating ladders for Venetian blinds comprising, in combination: a series of filler and spacer blocks; each block having a filler portion shaped to define a space corresponding to the space between successive cross connections of the finished ladder in use; each block including an extension below said filler portion, available for manipulation of said block; guide means for supporting a series of said blocks juxtaposed in a horizontal row; said extensions being shaped to abut each other in said row; said filler portions being shaped to define transverse spaces between adjacent filler portions for receiving the crossing portions of ladder tapes; advancing means for intermittently advancing said row longitudinally a distance equal to one space; side tape feed means for positioning side tapes along said row of blocks adjacent the filler portions of said blocks; means for lacing ladder tapes to and fro around said filler portions before they pass said side tape feed means; inserting means for moving new blocks upward from below one at a time into the spaces between said ladder tapes; said advancing means operating after said inserting means to engage the newly inserted block and force it to join the row and push the row forward; automatic withdrawal means operating in timed sequence before said advancing means, for withdrawing the leading block of the row; ailixing means in the nature of electronic welding electrodes operating after each actuation of said advancing means and before the succeeding operation of said advancing means for affixing said side tapes to the ladder type sections in contact with said side tapes; means for winding up the finished ladder coming from said row; return conveyor means for returning blocks withdrawn from the front of said row and carrying them back to be delivered to said inserting means; and means for actuating the moving elements of said equipment in predetermined time sequence.

4. Equipment for fabricating ladders for Venetian blinds comprising, in combination: a series of filler and spacer blocks; each block having a filler portion shaped to define a space corresponding to the space between successive cross connections of the finished ladder in use; each block including an extension below said filler portion, available for manipulation of said block; guide means for supporting a series of said blocks juxtaposed in a horizontal row; said extensions being shaped to abut each other in said row; said filler portions being shaped to define transverse spaces between adjacent filler portions for receiving the crossing portions of ladder tapes; advancing means for intermittently advancing said row longitudinally a distance equal to one space; side tape feed means for positioning side tapes along said row of blocks adjacent the filler portionsof said blocks; means for lacing ladder tapes toand fro around said filler portions beforethey pass said side tape feed means; inserting means for moving new blocks upward from below one at a time into the spaces between said ladder tapes; said advancing means operating after said inserting means to engage the newly inserted block and force it to join the row and push the row forward; automatic withdrawal means operating in timed sequence before said advancing means, for withdrawing the leading block of the row; and aflixing means in the nature of electronic welding electrodes operating after each actuation of said advancing means and before the succeeding operation of said advancing means for aflixing said side tapes to the ladder tape sections in contact with said side tapes.

5. Equipment for fabricating ladders for Venetian blinds comprising, in combination: a series of filler and spacer blocks; each block having a filler portion shaped to define a space corresponding to the space between successive cross connections of the finished ladder in use; each block including an extension below said filler portion, available for manipulation of said block; guide means for supporting a series of said blocks juxtaposed in a horizontal row; said extensions being shaped to abut each other in said row; said filler portions being shaped to define transverse spaces between adjacent filler portions for receiving crossing portions of ladder tape; advancing means for intermittently advancing said row longitudinally a distance equal to one space; side tape feed means for positioning side tapes along said row of blocks adjacent the filler portions of said blocks; means for lacing a ladder tape to and fro around said filler portions before they reach said side tape feed means; and affixing means for affixing said side tapes to the ladder tape in contact with said side tapes.

CARL J. DELEGARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,001,693 Rockwood May 14, 1935 2,017,450 Van Veen Oct. 15, 1935 2,123,817 Warren July 12, 1938 2,290,634 Clark, Jr. July 21, 1942 2,372,617 Trew Mar. 27, 1945 2,405,579 Hunter Aug. 13, 1946 2,488,355 Wagner Nov. 15, 1949 2,527,627 Frankel et al. Oct. 31, 1950 FOREIGN PATENTS Number Country Date 684,202 Germany Nov. 24, 1939 

